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 Post subject: R65C02P4 fake chips
PostPosted: Mon Jan 27, 2020 5:34 pm 
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I purchased five of this ICs off eBay. This is what arrived: Manufacturing date 2019. On the top, Mexico, on the bottom, Taiwan and a handful of scratches.
I wouldn't mind much if they worked. I hooked them up on a breadboard, providing power (5V) and tying reset, IRQ, NMI and SO high by 1K resistors. 1 Mhz clock courtesy of my function generator and later by a crystal. Data bus set to EA by 1k resistors. Power consumption is about 30 mA.

This is what I'm observing on all ICs:
-Current raises to 250 mA when reset pin is grounded.
-No clock output on PHI1 and PHI2
-No activity on address or data bus. (I cached some on one specific address pin at one time, but gone after reset).
-Some address lines are high, others low and others sit in between.

I'm pretty sure they are dead. But that the same symptoms appear on all five makes me suspect that my setup is wrong. Any ideas?
Juan


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 Post subject: Re: R65C02P4 fake chips
PostPosted: Mon Jan 27, 2020 5:56 pm 
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They could be a completely different chip, relabelled. If your time is precious, or your money, I'd recommend you reject them and get a refund.

But of course if you are curious, you might wonder what they really are.


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 Post subject: Re: R65C02P4 fake chips
PostPosted: Mon Jan 27, 2020 6:18 pm 
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I ordered and received 5 very similar marked chips in late 2018. They arrived with 2019 date codes. All 5 chips seem to be nmos 6502 relabelled as cmos parts.


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 Post subject: Re: R65C02P4 fake chips
PostPosted: Mon Jan 27, 2020 7:17 pm 
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I check some of the 40 pin chips I've acquired over the years, those reverse markings look a lot like those on an Atmel AT89C51 micro controller.

Attachment:
File comment: Not a great photo I'm afraid
at29C51 reverse.jpg
at29C51 reverse.jpg [ 81.23 KiB | Viewed 1757 times ]


No a great photo, but hopefully you'll be able to see the similarity of the font, and the format of the text. which on my chip is 0C3206-19651L on the top row and 1-U 0C0045 on the lower


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 Post subject: Re: R65C02P4 fake chips
PostPosted: Mon Jan 27, 2020 7:33 pm 
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In case it helps, here's a photo of a couple of P4s, a P3 and a P2 I bought last year.

Attachment:
IMG_20200128_041934.jpg
IMG_20200128_041934.jpg [ 622.42 KiB | Viewed 1751 times ]


Looks like the fakers are imitating the old '90s printing instead of using the new 21st century font?

None of my Rockwell chips (I have a couple of Ps, as well) have any markings on the bottom.

I've not yet tested any of these, though I can certainly wire up a NOP pullup/down and see what my oscilloscope says it's doing, if anybody's particularly concerned. (Or maybe even whack them into my Apple I replica if there's real doubt about whether or not they're CMOS parts.)

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 Post subject: Re: R65C02P4 fake chips
PostPosted: Mon Jan 27, 2020 8:57 pm 
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(I've a feeling in previous discussions of this sort we've wondered whether you can figure out which pins are inputs and which outputs, as they have characteristic circuits inside. If the Is and Os don't match up to the expected pinout, it's certainly not what it claims to be.)


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 Post subject: Re: R65C02P4 fake chips
PostPosted: Mon Jan 27, 2020 9:43 pm 
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RDY and BE are other pins you should tie high with resistors. But they shouldn't affect Phi1/Phi2 outputs.


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 Post subject: Re: R65C02P4 fake chips
PostPosted: Mon Jan 27, 2020 10:41 pm 
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Chromatix wrote:
RDY and BE are other pins you should tie high with resistors. But they shouldn't affect Phi1/Phi2 outputs.


Rockwell R65C02 chips are pin compatible with the 6502 and not the WDC 65C02. They don't have a bus enable (BE) or a vector pull.

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 Post subject: Re: R65C02P4 fake chips
PostPosted: Mon Jan 27, 2020 10:50 pm 
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BigEd wrote:
They could be a completely different chip, relabelled. If your time is precious, or your money, I'd recommend you reject them and get a refund.

But of course if you are curious, you might wonder what they really are.


I already asked for a refund. If they don't ask for them back, I may investigate further. You could always (attempt to) de-cap it and see what's what. They may micro controllers as Martin A pointed out
I will try to get some 6502s from reputable suppliers, albeit more expensive. Or I could have another go at ebay's lottery...


Chromatix wrote:
RDY and BE are other pins you should tie high with resistors. But they shouldn't affect Phi1/Phi2 outputs.


Yes, did that too. Sorry I missed that.
Also both supposedly GND pins (1 and 21) are not connected internally, don't know if this would be expected, although I would suppose they should be.


cjs wrote:
I've not yet tested any of these, though I can certainly wire up a NOP pullup/down and see what my oscilloscope says it's doing, if anybody's particularly concerned. (Or maybe even whack them into my Apple I replica if there's real doubt about whether or not they're CMOS parts.)


I would test them just in case. But it seems people are having different luck, so who knows.

By the way, the eBay seller I bought from was adeleparts2010.

Juan


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 Post subject: Re: R65C02P4 fake chips
PostPosted: Mon Jan 27, 2020 11:55 pm 
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BitWise wrote:
Chromatix wrote:
RDY and BE are other pins you should tie high with resistors. But they shouldn't affect Phi1/Phi2 outputs.

Rockwell R65C02 chips are pin compatible with the 6502 and not the WDC 65C02. They don't have a bus enable (BE) or a vector pull.

That may be true, but when you already know it's a mis-labelled part, you should anticipate it being some random 6502 variant (at best) and make only conservative assumptions.


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 Post subject: Re: R65C02P4 fake chips
PostPosted: Tue Jan 28, 2020 2:43 am 
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Rockwell hasn't made 6502 products in many years—what you have are counterfeits. The only contemporary supplier of 65C02 microprocessors is WDC. Why do people go to eBay for something that can be gotten through a 100 percent legit source? Demand your money back and report the supplier for selling fake product.

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 Post subject: Re: R65C02P4 fake chips
PostPosted: Tue Jan 28, 2020 3:27 am 
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It looks like the top of the chip has been sanded to remove the original markings, then printed with the Rockwell bits. Needless to say, I think they're just selling junk parts with markings for whatever they think they can sell.

I also agree with BDD.... why buy suspect old parts on eBay when you can buy new currently in production parts which are certainly much better with higher clock speeds, etc.?

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 Post subject: Re: R65C02P4 fake chips
PostPosted: Tue Jan 28, 2020 3:54 am 
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BigDumbDinosaur wrote:
Rockwell hasn't made 6502 products in many years—what you have are counterfeits. The only contemporary supplier of 65C02 microprocessors is WDC.

How long has it been? As seen above, I have a couple of parts with 2010 date codes on them, and I even have an R6502P (NMOS, not CMOS, though now I'm feeling I'd better check that) with a 1349 date code in my Apple 1 replica. (That CPU came as part of the kit, and seems to work fine.)

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Why do people go to eBay for something that can be gotten through a 100 percent legit source?

Because they can be soooooo cheap. Two of mine (I can't remember which ones, but I think the P2 and P3, which look like pulls from old boards) came from this AliExpress listing. Not only is $1/ea itself close to one tenth the cost of a W65C02 from Mouser, but Mouser would have charged me $20 or more for shipping. (Shipping for mine was "free.") When I happened to stumble across that, $2 seemed worth the risk, even if just to see if one gets working CPUs or not for that price.

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 Post subject: Re: R65C02P4 fake chips
PostPosted: Tue Jan 28, 2020 2:59 pm 
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BigDumbDinosaur wrote:
Rockwell hasn't made 6502 products in many years—what you have are counterfeits. The only contemporary supplier of 65C02 microprocessors is WDC. Why do people go to eBay for something that can be gotten through a 100 percent legit source?
Cost, clearly. It's easy to get legit WDC parts for those located in the US and presumably some other countries, but for the rest of us the shipping is many times the cost of the chip itself, and then there are other costs and charges in addition to that, particularly if one tries to reduce the shipping-to-parts ratio by including more parts. I for one has stopped ordering anything from the 'big' ones (Mouser, DigiKey, Jameco) due to this. Fortunately I got a stash of WDC parts before shipping costs exploded, but I can easily understand why people look at Ebay first. (After all, Ebay works perfectly fine for tons of other parts).

@cjs: "I have a couple of parts with 2010 date codes on them"

Those are fakes (or at least the date is fake). Rockwell stopped existing in 2001.


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 Post subject: Re: R65C02P4 fake chips
PostPosted: Wed Jan 29, 2020 12:26 pm 
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Tor wrote:
@cjs: "I have a couple of parts with 2010 date codes on them"
Those are fakes (or at least the date is fake). Rockwell stopped existing in 2001.

Perhaps I'm reading the date codes wrong?

I guess it's possible that the R65C02P4 chips in my photo above were relabeled to a faster part number, so as to attract customers (they were about the same price as other vendors), but that hardly seems worth the effort.

On the other hand, the CPU in my Apple I replica is labeled, "R6502P 13500-13 MEXICO 1349 B50323-8 [Rockwell logo]." And it definitely works at least as far as the monitor, BASIC and my own minor hacking so far goes. What on earth that works reasonably well as a 6502 would you re-label as a 1 MHz NMOS part?

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